I have had two bad crashes. On one, I broke my collar bone, shoulder blade, ulna (elbow) in 2 places and 2 ribs. I was back on the trainer in 2 weeks and on the road in 6. It did take 2 years before I could go over a small bump without real pain in my elbow. That negative feedback conditioned me to really avoid road blemishes part of it without noticing that it happened.

The other crash was a concussion and I was knocked cold and I wasn't "right" for about a month (I ran out of steam and had to nap during the day and I had trouble concentrating). That one was worse emotionally because it was like being killed in that I lost consciousness.

Both of my crashes happened in fast pacelines and both were caused by "squirrels". The rational thing to do would be to avoid fast pacelines with suspected squirrels in them, however, I find that I just get so uncomfortable in any fast paceline now that I can not ride in them. Maybe it will wear off and maybe it won't, but fast paceline riding was never a real big thing in my cycling anyway. I enjoyed doing it but it was not the center of my cycling motivation like it is for some people.

In my case, my injuries really did not affect my activity level. I think for any active person to be confined to a wheel chair would be enough to drive them around the bend. It would drive me nuts.

In cycling, one can control the risk level to a pretty large extent. You can probably figure out how you crashed and avoid doing something similar to it again. However, you can not reduce your risk to very near zero like you can for some other forms of exercise like walking and running.